Bluelabel

Bluelabel

Well Known Member
I hate asking stupid questions... but I tried to go right to the source and the only email address I could find for Sport Craft Antennas bounced and the phone number doesn?t answer...
I?ll keep this short.
We have a Bob Archer wing Tip VOR antenna installed in our RV-10. We are close to final assembly. At the moment I have the coax coiled up on the wing with enough to run into the plane and to the Garmin in one continuous feed. This, however is really making it difficult to finish a few things off as we can?t close any panels up until the plane goes to the airport and we put on the wings.
I know that NOT having a connector in the feed would be BETTER. But? the question is, if we put a coupling inline (could do BNC, or F Con. whatever would be most solid. I have the tools to do virtually any connector), will it REALLY degrade the signal? to a point I would notice?
IF we went ahead and ran the wire in the plane and had a connection point at the wing root, it would really make life right now easier. HOWEVER, this will be an IFR plane and I like ILS approaches? so, I don?t want to shoot myself in the foot.
Thanks for your time.
 
One extra BNC connection in the VOR cable won't make much difference, just do it.
 
BNC connector

A BNC will work good but with each connector you will lose some performance like you said. I don't know how much signal loss there will be but I have heard 15% or so per connector.
 
I have several connections and a splitter between the Archer antenna in my wingtop and the KX155 it is connected to. I can still get the ODI VOR from > 100nm when above 10K, and out to about 70nm when as low as 4000ft.

The signal loss from the additional connector is more academic than practical; the service volume of a high/low/terminal VOR along with your receiver will likely be a bigger influence.
 
Bluelabel said:
I hate asking stupid questions... but I tried to go right to the source and the only email address I could find for Sport Craft Antennas bounced and the phone number doesn?t answer...
I?ll keep this short.
We have a Bob Archer wing Tip VOR antenna installed in our RV-10. We are close to final assembly. At the moment I have the coax coiled up on the wing with enough to run into the plane and to the Garmin in one continuous feed. This, however is really making it difficult to finish a few things off as we can?t close any panels up until the plane goes to the airport and we put on the wings.
I know that NOT having a connector in the feed would be BETTER. But? the question is, if we put a coupling inline (could do BNC, or F Con. whatever would be most solid. I have the tools to do virtually any connector), will it REALLY degrade the signal? to a point I would notice?
IF we went ahead and ran the wire in the plane and had a connection point at the wing root, it would really make life right now easier. HOWEVER, this will be an IFR plane and I like ILS approaches? so, I don?t want to shoot myself in the foot.
Thanks for your time.
Click to expand...

Hmmm...what seems to be the issue preventing you from closing things up? I just connected everything on the panel, ran the wires to the wing root area and coiled them up. Then, when putting the wings on, pull them through the conduit. No need for connectors and it didn't hinder or slow anything.
 
I have a connector in line with my Archer VOR antenna. The connector is inside the fuselage, and is a BNC-BNC bulkhead connector passing through the outboard seat rib (one bay inboard of the passenger side wall). The antenna gets great reception and has been problem-free. That is, once I figured out I needed to use an insulated/isolated bulkhead connector.

The first bulkhead connector I had was not insulated, so the braid of the RG400 cable was well grounded to the airframe at the seat rib. In my test flights, I immediately suspected the bulkhead connector as a problem when I could get almost no VOR reception and just a bunch of noise on the audio output. Swapping it for the insulated connector fixed the problem, and it's been great since.
 
Losses

RV3bpilot said:
A BNC will work good but with each connector you will lose some performance like you said. I don't know how much signal loss there will be but I have heard 15% or so per connector.
Click to expand...

I hope it's not 15% :eek:

Amphenol specifies 2.3% loss (0.2 dB) for it's BNC connectors and that's at 3 GHz.

Just install the correct connector specified for the co-ax you are using.
 
RV7A Flyer said:
Hmmm...what seems to be the issue preventing you from closing things up? I just connected everything on the panel, ran the wires to the wing root area and coiled them up. Then, when putting the wings on, pull them through the conduit. No need for connectors and it didn't hinder or slow anything.
Click to expand...

The coax is soldered on to the antenna and run through the wing with a coil to run to the panel. It's literally the last thing to connect.
 
Bluelabel said:
The coax is soldered on to the antenna and run through the wing with a coil to run to the panel. It's literally the last thing to connect.
Click to expand...

Sounds like you got things a tad backwards there, then. Desolder it and reverse the process.

I don't like connectors, and try to minimize them whenever possible...they are sources of signal loss, corrosion, RF problems, etc., not to mention just plain old disconnections. And that's IF the installer did his job right (that'd be me) and made good crimps and connector installations, so the wires don't come loose from the pins/sockets.

Desolder the connectors on the (easy to work on) end at the antenna, route the cable from the radio through the cockpit, fuse, etc., to the wing root, coil it up and then pull it through the wing when installing the wings for the final time. Then just put the connector back on at the antenna end. Easy peasy.
 
Oh, and remember...a bulkhead connector is not *one* connection, it's two, one on each side, thereby doubling your chances of all of the above-mentioned problems.
 
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